1. Field of the Invention
The present invention relates to a treatment solution for ink-jet recording, a water-based ink set for ink-jet recording, an ink-jet recording method, and an ink-jet recording apparatus.
2. Description of the Related Art
The ink-jet recording is carried out in some cases by using a treatment solution (process liquid) blended with polyallylamine (PAA) in order to improve the optical density (OD value) of a recorded image recorded with a water-based ink based on the use of a pigment ink (see, for example, Japanese Patent Application Laid-open No. 11-314449). PAA, which is contained in the treatment solution as described above, can aggregate the pigment contained in the water-based ink on the recording medium. As a result, the optical density (OD value) of the recorded image is improved.
However, if the treatment solution, which contains PAA, is thawed, for example, after the treatment solution is frozen during the use in a cold district or during the transportation by an airplane or the like, the treatment solution causes the phase separation. Further, if the treatment solution is exposed to a high temperature environment, for example, during the transportation or the storage in a warehouse in summer, a color of the treatment solution is changed (the treatment solution undergoes color-change). Thus, the treatment solution, which contains PAA, involves such a problem that the storage stability is insufficient in the low temperature environment and the high temperature environment.